Method for producing organic thin film device and transfer material used therein

ABSTRACT

A transfer material comprising an organic thin film uniformly provided by a wet method, etc. with high productivity is used to efficiently produce an organic thin film device such as an organic EL device excellent in light-emitting efficiency, uniformity of light emission and durability. A method for producing the organic thin film device according to the present invention comprises the steps of: making an organic thin film  112  of a transfer material  110  face a transparent electrically conductive layer  102  disposed on a support  101 , the transfer material  110  having the organic thin film  112  on a temporally substrate  111 ; decompressing a space  105  between the transfer material  110  and the transparent electrically conductive layer  102  to bring the transfer material  110  in contact to the transparent electrically conductive layer  102 ; heating at least one organic thin film  112 ; and peeling the temporary substrate  111  from the organic thin film  112  to transfer the organic thin film  112  to the transparent electrically conductive layer  102.

FIELD OF THE INVENTION

[0001] The present invention relates to a method for producing anorganic thin film device and a transfer material usable for the method,particularly to a method of providing an organic thin film of an organicEL device (organic electroluminescent device).

BACKGROUND OF THE INVENTION

[0002] Recently, much attention has been paid to organic light-emittingdevices such as organic EL devices that can be easily applied to asurface light-emitting device. Specifically, the organic light-emittingdevice has been considered to be useful as an economical, solid emissiontype, light-emitting device having a large emission area such as a fullcolor display device and a writing light source array, thereby havingbeen actively studied. The organic light-emitting device generallycomprises a couple of electrodes, a transparent electrode and a backside electrode, and a light-emitting organic thin film disposed betweenthe electrodes. When to the organic light-emitting device is applied anelectric field, electrons are injected from the back side electrode andholes are injected from the transparent electrode to the light-emittingorganic thin film. The electrons and the holes are re-combined in thelight-emitting organic thin film and energy is converted into lightwhile an energy level is turned from a conduction band to a valenceband, whereby the organic light-emitting device emits light.

[0003] The organic thin film in the organic light-emitting device hasbeen generally provided by a vapor deposition process. Patterningmethods for the organic thin film have been proposed in view ofdevelopment of color image emission. For example, U.S. Pat. No.5,294,869 disclosed a patterning method using a shadow mask. However,this patterning method needs a complicated vapor deposition apppratus tobe poor in productivity and positional accuracy of patterning.

[0004] To overcome the above problems in patterning, Japanese PatentLaid-Open No. 9-167684 disclosed a method where an organic thin film isuniformly provided on a mica temporary substrate by a vapor depositionprocess beforehand, and the organic thin film is disposed closer to asubstrate and selectively vapor-deposited onto the substrate in apattern. Further, Japanese Patent Laid-Open No. 2000-195665 disclosed amethod where an organic thin film is uniformly provided on a filmtemporary substrate by a vapor deposition process beforehand, and theorganic thin film is disposed closer to a substrate through a mask andvapor-deposited onto the substrate in a pattern of the mask. Thesemethods using the vapor deposition source provided on the temporarysubstrate are disadvantageous in that the vapor deposition process ispoor in productivity and that only a low molecular weight organiccompound can be used for the organic thin film.

[0005] Polymer-type organic light-emitting devices using alight-emitting organic thin film made of a polymer or a low molecularweight organic compound dispersed in a binder resin also have beenknown. Examples of the polymer include poly(p-phenylenevinylene) forgreen light emission (Nature, Vol. 347, Page 539,1990),poly(3-alkylthiophene) for red-orange light emission (Japanese Journalof Applied Physics, Vol. 30, Page L1938, 1991), polyalkylfluorene bluelight emission (Japanese Journal of Applied Physics, Vol. 30, PageL1941,1991), etc. Such polymer-type organic light-emitting devices canbe easily increased in emitting area to be useful for a flexible device.However, the light-emitting organic thin film cannot be provided by avapor deposition process, whereby the light-emitting organic thin filmis generally provided by a wet method.

[0006] As a method for providing a patterned, light-emitting organicthin film of the polymer-type organic light-emitting device, an ink-jetmethod, a printing method, etc. have been proposed. However, thepatterned, light-emitting organic thin film provided by such a method isinsufficient in uniformity of thickness because of a surface tension ofa solution used in the method. Further, in the case of providing alaminate of a plurality of organic thin films, components is dissolvedand mixed around a boundary of each film. Thus, the polymer-type organiclight-emitting device utilizing the patterning method is poor inlight-emitting efficiency and durability.

[0007] Expectations are high for a plastic film of a high molecularweight material as a flexible substrate of the organic light-emittingdevice. However, the plastic film is poor in oxygen- andwater-resistance to be far from practicable, so that the substrate isgenerally made of a glass. The glass substrate is more difficult inhandling than the plastic film, thereby reducing productivity in wetmethod. Further, in the case of using the plastic film substrate, thetransparent electrode and a thin film transistor are laminated on thesubstrate to be costly. Coating such a substrate with the organic thinfilm is disadvantageous in yield and economical efficiency. Thus, therehas been increasing need for a patterning method usable for productionof the polymer-type organic light-emitting device.

[0008] WO 00/41893 disclosed a method using a donor sheet comprising anorganic thin film and a photo-thermal conversion layer, where theorganic thin film is thermally transferred to the substrate in a desiredpattern by a laser. Such a thermal transfer method is disadvantageous inthat a gas often penetrates into an interface between the organic thinfilm and the substrate. In the organic light-emitting device produced bythis method, light-emitting efficiency, durability and uniformity of alight-emitting surface depend on conditions of the interface, andlight-emitting properties are worsened by the penetration of a gas.

[0009] Further, in thermal writing-patterning method using a thermalhead or a laser that is utilized in printing technique, temperaturedistribution expands around the pattern due to thermal diffusivity sothat outlines of the organic thin film cannot be formed accurately.Thus, organic light-emitting devices produced by this method vary inamount of emission and has a defect due to an electric inferiority or abreak of the organic thin film to be poor in durability. Further, thereis a case where yield is lowered by poor positional accuracy of thesubstrate and the thermal head or the laser.

OBJECT AND SUMMARY OF THE INVENTION

[0010] An object of the present invention is to provide a method wherean organic thin film is uniformly provided by a wet method, etc., sothat an organic thin film device such as an organic EL device excellentin light-emitting efficiency, uniformity of light emission anddurability is efficiently produced with a simple apparatus and reducedcost. Another object of the present invention is to provide a transfermaterial usable in the method.

[0011] As a result of intense research in view of the above objects, theinventors have found that an organic thin film device such as an organicEL device excellent in light-emitting efficiency, uniformity of lightemission and durability can be produced with excellent efficiency andreduced cost by a method where an organic thin film is provided on atemporary substrate by a wet method, etc. and transferred to asubstrate. The present invention has been accomplished by the finding.

[0012] Thus, the first method for producing an organic thin film deviceaccording to the present invention comprises the steps of: making anorganic thin film of a transfer material face a substrate, the transfermaterial having the organic thin film on a temporally substrate;decompressing a space between the transfer material and the substrate tobring the transfer material in contact to the substrate; heating atleast one organic thin film; and peeling the temporary substrate fromthe organic thin film to transfer the organic thin film to thesubstrate.

[0013] In the first method, the organic thin film may be transferred tothe substrate in a minute pattern by the steps of: placing a mask havinga plurality of openings in the minute pattern between the transfermaterial and the substrate; decompressing spaces in the openings betweenthe transfer material and the substrate to bring the transfer materialin contact to the substrate; heating at least one organic thin film; andpeeling the temporary substrate from the organic thin film. Each of theopenings of the mask is preferably tapered from the transfer materialside to the substrate side. It is preferred that the mask has anaperture connected with the openings and the spaces are decompressedthrough the aperture. Further, the aperture preferably comprisesrecesses provided on the bottom of the mask. The mask is preferably madeof a material selected from the group consisting of metals, glasses,ceramics and heat resistant resins.

[0014] The second method according to the present invention is forproducing an organic thin film device where a laminate of a plurality ofcontinuous or patterned organic thin films is provided on a substrate byrepeating a peeling-transfer process. The peeling-transfer processcomprises the steps of: making an organic thin film of a transfermaterial face the substrate, the transfer material having the organicthin film on a temporally substrate; bringing the transfer material incontact to the substrate; heating at least one organic thin film; andpeeling the temporary substrate from the organic thin film to transferthe organic thin film to the substrate. In the second method, it ispreferred that the transfer material is brought in contact to thesubstrate while decompressing a space between the transfer material andthe substrate.

[0015] In the first and second methods according to the presentinvention, each of a blue light-emitting organic thin film, a greenlight-emitting organic thin film and a red light-emitting organic thinfilm may be transferred to the substrate in a minute pattern to providea light-emitting organic thin film comprising pixels of blue, green andred arranged repeatedly. The organic thin film is preferably heated at40 to 200° C. Further, it is preferred that the organic thin film isprovided on the temporally substrate by a wet method.

[0016] The third method for producing an organic thin film deviceaccording to the present invention comprises the steps of: making alight-emitting organic thin film comprising patterned pixels of blue,green and red of a transfer material face a substrate, the transfermaterial having the light-emitting organic thin film on a temporallysubstrate; bringing the transfer material in contact to the substrate;heating at least one light-emitting organic thin film; and peeling thetemporary substrate from the light-emitting organic thin film totransfer the light-emitting organic thin film to the substrate. In thethird method, it is preferred that the transfer material is Drought incontact to the substrate while decompressing a space between thetransfer material and the substrate. The light-emitting organic thinfilm is preferably heated at 40 to 200° C. Further, it is preferred thatthe light-emitting organic thin film is provided on the temporallysubstrate by a wet method.

[0017] A transfer material of the present invention comprises atemporary substrate and a light-emitting organic thin film provided onthe temporary substrate by a wet method, etc., the light-emittingorganic thin film comprising patterned pixels of blue, green and red.The transfer material of the present invention can be used in the thirdmethod.

[0018] The organic thin film device produced by the first, second orthird method preferably comprises a light-emitting organic thin film ora carrier-transporting organic thin film, more preferably comprises ahole-transporting organic thin film, a light-emitting organic thin filmand an electron-transporting organic thin film disposed in this orderfrom the substrate side. Further, the light-emitting organic thin filmpreferably comprises pixels of blue, green and red arranged repeatedly.The substrate preferably comprises a support and a transparentelectrically conductive layer disposed on the support.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019]FIG. 1(a) is a schematic, cross-sectional view showing anembodiment of the first method according to the present invention;

[0020]FIG. 1(b) is a top view showing the embodiment of FIG. 1(a);

[0021]FIG. 2 is a schematic, cross-sectional view showing a process ofdecompressing a space between a substrate and a transfer material ofFIG. 1(a);

[0022]FIG. 3 is a schematic, cross-sectional view showing an organicthin film transferred to the substrate of FIG. 1(a);

[0023]FIG. 4 is a schematic, cross-sectional view showing anotherembodiment of the first method according to the present invention;

[0024]FIG. 5(a) is a schematic, cross-sectional view shoving a Mask usedin a further embodiment of the first method according to the presentinvention;

[0025]FIG. 5(b) is a top view showing the mask of FIG. 5(a);

[0026]FIG. 6(a) is a schematic, cross-sectional view showing a transfermaterial disposed on the mask of FIG. 5(a);

[0027]FIG. 6(b) is a schematic, cross-sectional view showing a processof decompressing spaces between a substrate and the transfer material ofFIG. 6(a);

[0028]FIG. 7 is a schematic, cross-sectional view showing an organicthin film transferred to the substrate of FIG. 6(a);

[0029]FIG. 8 is a schematic, cross-sectional view showing an example ofthe organic thin film device produced by the first method according tothe present invention;

[0030]FIG. 9 is a schematic, cross-sectional view showing production ofthe organic thin film device of FIG. 8;

[0031]FIG. 10 is a schematic, cross-sectional view showing an example ofthe organic thin film device produced by the second method according tothe present invention;

[0032]FIG. 11 is a schematic, cross-sectional view showing anotherexample of the organic thin film device produced by the second methodaccording to the present invention;

[0033]FIG. 12(a) is a schematic, cross-sectional view showing an exampleof the organic thin film device produced by the third method accordingto the present invention;

[0034]FIG. 12(b) is a top view showing the organic thin film device ofFIG. 12(a); and

[0035] FIGS. 13(a), 13(b), 13(c) and 13(d) are a schematic,cross-sectional view showing a further example of the organic thin filmdevice produced by the third method according to the present invention,respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] The first, second and third methods for producing an organic thinfilm device according to the present invention will be explained indetail below with reference to FIGS. 1 to 13, and the structure of theorganic thin film device will be explained in detail below withoutintention of restricting the scope of the present invention defined bythe claims attached hereto.

[0037] [1] Method for Producing Organic Thin Film Device

[0038] (1) First Method

[0039] FIGS. 1(a), 1(b), 2 and 3 show an embodiment of the first methodaccording to the present invention. On a support 101 is disposed atransparent electrically conductive layer 102 and a mask 103 such thatthe transparent electrically conductive layer 102 is enclosed by themask 103. The mask 103 comprises an aperture 104 connecting to a space105 between the transparent electrically conductive layer 102 and atransfer material 110. The aperture 104 is connected to a vacuumapparatus (not shown) through a pipe 115. The transfer material 110comprises a temporary substrate 111 and an organic thin film 112provided on a surface of the temporary substrate 111. The transfermaterial 110 wound on a roll 113 is rewound by a roll 114 such that thetransfer material 110 is moved while coming in contact with the mask103. Thus, the transfer material 110, the mask 103 and the transparentelectrically conductive layer 102 form the closed space 105 (FIGS. 1(a)and 1(b)). When the vacuum apparatus is operated in the state where thetransfer material 110 comes in contact with the mask 103, the space 105is decompressed so that the transfer material 110 is brought in tightcontact to the transparent electrically conductive layer 102 as shown inFIG. 2. Then, the organic thin film 112 of the transfer material 110 isheated by a thermal head, etc., to be bond to the transparentelectrically conductive layer 102. The temporary substrate 111 is peeledoff from the organic thin film 112 and the mask 103 is removed toproduce an organic thin film device where the continuous, organic thinfilm 112 is provIded on the transparent electrically conductive layer102 as shown in FIG. 3.

[0040]FIG. 4 is a schematic, cross-sectional view showing anotherembodiment of the first method according to the present invention. Aplate 120 moves with a roll 116 while coming in contact with the mask103. A space 106 enclosed by the transparent electrically conductivelayer 102 disposed on the support 101, the mask 103, the plate 120 andthe transfer material 110 connects to the aperture 104 in the mask 103.Thus, the organic thin film 112 of the transfer material 110 is broughtin tight contact to the transparent electrically conductive layer 102 bydecompressing the space 106. Then, the organic thin film 112 is heatedand the temporary substrate 111 is peeled off as above to produce anorganic thin film device where the continuous, organic thin film 112 isprovided on the transparent electrically conductive layer 102. In thismethod, because only a small area of the transfer material 110 comesinto contact with the transparent electrically conductive layer 102,there is little fear of air remaining between the organic thin film 112and the transparent electrically conductive layer 102.

[0041] FIGS. 5(a), 5(b), 6(a), 6(b) and 7 are a view showing a furtherembodiment of the first method according to the present invention,respectively. First, a mask 203 having openings 203 a in a minutepattern is brought in tight contact to a substrate, which comprises asupport 201 of a glass, etc. and a transparent electrically conductivelayer 202 disposed thereon. As shown in FIGS. 5(a) and 5(b), eachopening 203 a of the mask 203 may be tapered from the transfer materialside to the substrate side. Thus, each opening 203 a may have taperedportions 203 b. The openings 203 a communicates to an external vacuumapparatus through an aperture 204 formed on the back surface of the mask203. Then, the transfer material 110 is disposed on the upper portion ofthe mask 203, whereby spaces are formed by the transparent electricallyconductive layer 202, the transfer material 110 and the mask 203 (FIG.6(a)). The spaces in the openings 203 a are decompressed through theaperture 204 by the vacuum apparatus, thus, the transfer material 110 isformed into a shape corresponding to the tapered openings 203 a, wherebythe transfer material 110 comes into tight contact with the transparentelectrically conductive layer 202 only at the openings 203 a (FIG.6(b)). After heating the transfer material 110 and the transparentelectrically conductive layer 202, the temporary substrate of thetransfer material 110 is peeled off, so that an organic thin film 210 istransferred to the transparent electrically conductive layer 202 in theminute pattern correspondingly to the openings 203 a (FIG. 7). Transferof the organic thin film in portions 210 a is prevented by the mask 203.

[0042] A multi-color light-emitting organic thin film 310 shown in FIG.8 may be provided by the above-mentioned mask having the openings in theminute pattern. The multi-color light-emitting organic thin film 310comprises a plurality of light-emitting units 310 a composed of a bluepixel 311, a green pixel 312 and a red pixel 313. The light-emittingunits 310 a are on the whole surface of the multi-color light-emittingorganic thin film 310 uniformly. The blue pixels 311 are provided on atransparent electrically conductive layer 302 disposed on a support 301as above, then, a mask 303 is set in the predetermined position suchthat half of a non-transferred region 310 b is covered with the mask 303as shown in FIG. 9. Then, a green light-emitting organic thin film istransferred to the half of the non-transferred region 310 b to providethe green pixels 312 by the same steps as described for FIGS. 6(a) and6(b) of: placing a transfer material comprising a temporary substrateand a green light-emitting organic thin film on the mask 303;decompressing and heating; and peeling off the temporary substrate.Equally, the red pixels 313 are provided by the steps of: setting themask 303 in the predetermined position such that remaining half of thenon-transferred region 310 b is covered with the mask 303; placing atransfer material comprising a temporary substrate and a redlight-emitting organic thin film on the mask 303; decompressing andheating; and peeling off the temporary substrate.

[0043] (2) Second Method

[0044]FIG. 10 is a schematic, cross-sectional view showing an example ofthe organic thin film device produced by the second method according tothe present invention. In FIG. 10, an organic thin film 400 is providedon a transparent electrically conductive layer 402 disposed on a support401, the organic thin film 400 comprising a hole-transporting organicthin film 410, a light-emitting organic thin film 420 and anelectron-transporting organic thin film 430. Each of the organic thinfilms 410, 420 and 430 are provided by the above-mentionedpeeling-transfer process in order, to form the organic thin film 400.Specifically, the hole-transporting organic thin film 410 is provided ona surface of a temporary substrate to prepare a first transfer material,and the first transfer material is moved while coming into contact witha mask in the same manner as described for FIG. 1. Then, a spaceenclosed by the first transfer material, the mask and the transparentelectrically conductive layer 402 is decompressed so that the firsttransfer material is brought in tight contact to the transparentelectrically conductive layer 402. The hole-transporting organic thinfilm 410 of the first transfer material is heated, the temporarysubstrate is peeled off from the hole-transporting organic thin film 410and the mask is removed, to transfer the hole-transporting organic thinfilm 410 to the transparent electrically conductive layer 402 into acontinuous surface shape. Next, the light-emitting organic thin film 420is provided on a surface of the other temporary substrate to prepare asecond transfer material, and the second transfer material is disposedon the hole-transporting organic thin film 410 in contact with a mask. Aspace enclosed by the second transfer material, the mask and thehole-transporting organic thin film 410 is decompressed so that thesecond transfer material is brought into tight contact to thehole-transporting organic thin film 410. The light-emitting organic thinfilm 420 of the second transfer material is heated, the temporarysubstrate is peeled off from the light-emitting organic thin film 420and the mask is removed, to transfer the light-emitting organic thinfilm 420 to the hole-transporting organic thin film 410 into acontinuous surface shape. Equally, the electron-transporting organicthin film 430 is provided on a temporary substrate to prepare a thirdtransfer material and transferred onto the light-emitting organic thinfilm 420.

[0045]FIG. 11 is a schematic, cross-sectional view showing anotherexample of the organic thin film device produced by the second methodaccording to the present invention. In FIG. 11, an organic thin film 500is provided on a transparent electrically conductive layer 502 disposedon a support 501, the organic thin film 500 comprising ahole-transporting organic thin film 510, a light-emitting organic thinfilm 520 and an electron-transporting organic thin film 530. Thelight-emitting organic thin film 520 comprises a plurality oflight-emitting units 520 a composed of a blue pixel 321, a green pixel522 and a red pixel 523. The light-emitting units 520 a are disposed onthe whole surface of the light-emitting organic thin film 520 uniformly.The hole-transporting organic thin film 510 is transferred to thetransparent electrically conductive layer 502 in the same manner asdescribed for FIG. 10, and then, the multi-color light-emitting organicthin film 520 is transferred onto the hole-transporting organic thinfilm 510 in the same manner as the multi-color light-emitting organicthin film 310 shown in FIG. 8. Finally, the electron-transportingorganic thin film 530 is transferred onto the light-emitting organicthin film 520 in the same manner as described for FIG. 10.

[0046] (3) Third Method

[0047] A transfer material used in the third method of the presentinvention comprises a temporary substrate and a light-emitting organicthin film provided thereon by a wet method, etc., the light-emittingorganic thin film comprising pixels of blue, green and red, which areformed in a predetermined pattern, respectively. FIGS. 12(a) and 12(b)are a view showing an example of the organic thin film device producedby the third method, respectively. The light-emitting organic thin film610 shown in FIGS. 12(a) and 12(b) comprises a plurality oflight-emitting units 610 a composed of a blue pixel 611, a green pixel612 and a red pixel 613. The light-emitting units 610 a are disposed onthe whole surface of a transparent electrically conductive layer 602provided on a support 601 uniformly. Each of the pixels 611, 612 and 613may be formed in a stripe pattern as shown in FIG. 12(b), or in atwo-dimensional grid pattern, etc.

[0048] In the third method, the other organic thin film may be providedin combination with the patterned, light-emitting organic thin film toform a laminate on a substrate. A method for providing the other organicthin film is not particularly limited. The substrate may be coated withthe other organic thin film by a wet method. A transfer materialcomprising a temporary substrate and the uniform other organic thin filmmay be prepared to transfer the other organic thin film to the substrateby a peeling-transfer process. Further, the other organic thin film maybe provided on the patterned, light-emitting organic thin film by a wetmethod to prepare a transfer material comprising a temporary substrateand a multi-layer organic thin film, then, the multi-layer organic thinfilm may be transferred to the substrate. Furthermore, the laminate ofthe patterned, light-emitting organic thin film and the other organicthin film may be provided on the substrate by repeating thepeeling-transfer process in the same manner as the second methodmentioned above. In the case where the light-emitting organic thin filmand the other organic thin film have similar solvent-solubility, suchlaminate is preferably formed by repetition of the peeling-transferprocess. Examples of the organic thin film device comprising suchlaminate will be described with reference to FIGS. 13(a), 13(b), 13(c)and 13(d) without intention of restricting the scope of the presentinvention defined by fhe claims attached hereto.

[0049] In FIG. 13(a), a laminate 700 a is provided on a transparentelectrically conductive layer 702 disposed on a support 701. Tnelaminate 700 a comprises a hole-transporting organic thin film 710 a, alight-emitting organic thin film 720 a and an electron-transportingorganic thin film 730 a. The light-emitting organic thin film 720 acomprises pixels of blue, green and red 721 a, 722 a and 723 a. Each ofthe organic thin films 710 a, 720 a and 730 a is formed by thepeeling-transfer process using the temporary substrate. Specifically,the hole-transporting organic thin film 710 a is provided on a temporarysubstrate to prepare a first transfer material, and thehole-transporting organic thin film 710 a is transferred onto thetransparent electrically conductive layer 702 by the peeling-transferprocess using the first transfer material. Then, the light-emittingorganic thin film 720 a is provided on a temporary substrate to preparea second transfer material, and the light-emitting organic thin film 720a is transferred onto the hole-transporting organic thin film 710 a bythe peeling-transfer process using the second transfer material.Finally, the electron-transporting organic thin film 730 a is providedon a temporary substrate to prepare a third transfer material, and theelectron-transporting organic thin film 730 a is transferred onto thelight-emitting organic thin film 720 a by the peeling-transfer processusing the third transfer material.

[0050] In FIG. 13(b), a laminate 700 b is provided on the transparentelectrically conductive layer 702 disposed on the support 701. Thelaminate 700 b comprises a hole-transporting organic thin film 710 b, alight-emitting organic thin film 720 b and an electron-transportingorganic thin film 730 b. The light-emitting organic thin film 720 bcomprises pixels of blue, green and red 721 b, 722 b and 723 b. Thoughthe structure of the laminate 700 b is the same as that of the laminate700 a, they differ from each other in forming method. In the laminate700 b, only the light-emitting organic thin film 720 b is formed by thepeeling-transfer process, and the hole-transporting organic thin film710 b and the electron-transporting organic thin film 730 b are formedby a wet-type coating method. Specifically, the hole-transportingorganic thin film 710 b is provided on the transparent electricallyconcuctive layer 702 by the wet-type coating method, and then, thelight-emitting organic thin film 720 b is provided on a temporarysubstrate to prepare a transfer material and the light-emitting organicthin film 720 b is transferred onto the hole-transporting organic thinfilm 710 b by the peeling-transfer process using the transfer material.Finally, the electron-transporting organic thin film 730 b is providedon the light-emitting organic thin film 720 b by the wet-type coatingmethod.

[0051] In FIG. 13(c), a laminate 700 c is provided on the transparentelectrically conductive layer 702 disposed on the support 701. Thelaminate 700 c comprises a hole-transporting organic thin film 710 c, alight-emitting organic thin film 720 c and an electron-transportingorganic thin film 730 c. The light-emitting organic thin film 720 ccomprises pixels of blue, green and red 721 c, 722 c and 723 c. Thoughthe structure of the laminate 700 c is the same as that of the laminate700 a, they differ from each other in forming method. In the laminate700 c, the hole-transporting organic thin film 710 c and thelight-emitting organic thin film 720 c are formed by thepeeling-transfer process using the temporary substrate at the same time,and the electron-transporting organic thin film 730 c is formed by thewet-type coating method. Specifically, the hole-transporting organicthin film 710 c is provided on the temporary substrate by a wet method,the light-emitting organic thin film 720 c is provided on thehole-transporting organic thin film 710 c to prepare a transfermaterial, and the a laminate 740 of the hole-transporting organic thinfilm 710 c and the light-emitting organic thin film 720 c is transferredonto the transparent electrically conductive layer 702 by thepeeling-transfer process using the transfer material. Then, theelectron-transporting organic thin film 730 c is provided on thelight-emitting organic thin film 720 c by the wet-type coating method.

[0052] In FIG. 13(d), a laminate 700 d is provided on the transparentelectrically conductive layer 702 disposed on the support 701. Thelaminate 700 d comprises a hole-transporting organic thin film 710 d, alight-emitting organic thin film 720 d and an electron-transportingorganic thin film 730 d. The light-emitting organic thin film 720 dcomprises pixels of blue, green and red 721 d, 722 d and 723 d. Thoughthe structure of the laminate 700 d is the same as that of the laminate700 a, they differ from each other in forming method. In the laminate700 d, the hole-transporting organic thin film 710 d is formed by thewet-type coating method, and the light-emitting organic thin film 720 dand the electron-transporting organic thin film 730 d are formed by thepeeling-transfer process using the temporary substrate at the same time.Thus, the hole-transporting organic thin film 710 d is provided on thetransparent electrically conductive layer 302 by the wet-type coatingmethod. Then, the light-emitting organic thin film 720 d is provided onthe temporary substrate, the electron-transporting organic thin film 730d is provided on the light-emitting organic thin film 720 d by the wetmethod to prepare a transfer material, and the a laminate 750 of thelight-emitting organic thin film 720 d and the electron-transportingorganic thin film 730 d is transferred onto the hole-transportingorganic thin film 710 d by the peeling-transfer process using thetransfer material.

[0053] (4) Transfer Material

[0054] (a) Temporary Substrate

[0055] The temporary substrate used in the present invention ispreferably made of a material that has chemical-stability,thermal-stability and flexibility. Preferred examples of the materialinclude: fluorine resins such as a tetrafluoroethylene resin (PTFE),trifluororephthalate and polyethylene naphthalate (PEN); polyarylate;polycarbonate; polyolefin such as polyethylene and polypropylene;polyethersulfone (PES); etc. The temporary substrate is particularlypreferably a thin sheet of such a material or a laminate thereof. Thetemporary substrate preferably has thickness of 1 to 300 μm. In the caseof forming the organic thin film in a minute pattern, the thickness isparticularly preferably 3 to 20 μm.

[0056] (b) Formation of Organic Thin Film on Temporary Substrate

[0057] The organic thin film comprising a high molecular weight compoundas a binder is preferably provided on the temporary substrate by a wetmethod. For example, materials for the organic thin film are dissolvedin an organic solvent at predetermined concentrations, and the temporarysubstrate is coated with thus-obtained solution to provide the organicthin film. Method of coating is not particularly limited if only it canform the organic thin film that has a thickness of 200 nm or less anduniform thickness distribution after drying. Examples of the method ofcoating include: spin coating methods; screen printing methods; gravurecoating methods such as micro-gravure coating methods; dip coatingmethods; casting methods; die coating methods; roll coating methods; barcoating methods; extrusion coating methods; ink-jet coating methods;etc. The extrusion coating methods of roll-to-roll high in productivityare preferred in the first and second methods of the present invention,and the micro-gravure coating methods and the ink-jet coating methodsare preferred for patterning in the third method of the presentinvention.

[0058] The light-emitting organic thin film comprising patterned pixelsof blue, green and red used in the third method may be provided byapplying coating solutions each containing a light-emitting compound fora color through a mask into a predetermined pattern in order. Materialfor the mask is not limited, and the mask is preferably made of such aneconomical material high in durability as a metal, a glass, a ceramic, aheat resistant resin, etc. A plurality of the materials may be used incombination with each other. Thickness of the mask is preferably 2 to100 μm, more preferably 5 to 60 μm from the viewpoints of mechanicalstrength and accuracy in patterning of pixels.

[0059] (5) Laminate

[0060] In the case where the laminate of a plurality of the organic thinfilms is provided on the substrate, the temporary substrate may bestacked wifn the organic thin films to transfer the organic thin filmsto the substrate. The laminate may be provided by repeating thepeeling-transfer process in order as described for the second method ofthe present invention. Further, a method other than the peeling-transferprocess may be used in combination therewith. In the case where twoorganic thin films adjacent to each other have similarsolvent-solubility, the laminate is preferably formed by repeating thepeeling-transfer process.

[0061] (6) Peeling-Transfer Process

[0062] In the present invention, the organic thin film is formed by thepeeling-transfer process. In the peeling-transfer process, the organicthin film is softened by heating and bond to the transparentelectrically conductive layer or the other organic thin film, and then,the temporary substrate is peeled off from the organic thin film totransfer and leave only the organic thin film thereonto. Heating may beachieved by means of a laminator, an infrared heater, a thermal head,etc. Specifically, “First Laminator Va.-400 III” manufactured byTAISEI-LAMINATOR. CO., a thermal head for thermal transfer printing,etc. may be used in this invention. Heating temperature is notparticularly limited and may be selected depending on the material usedfor the organic thin film. In general, the heating temperature ispreferably 40 to 200° C., particularly preferably 60 to 150° C.

[0063] (7) Mask

[0064] In the case of placing the mask between the transfer material andthe substrate, Material for the mask is not particularly limited, andpreferably such an economical material with high durability as a metal,a glass, a ceramic, a heat resistant resin, etc. A plurality of thematerials may be used in combination with each other. Thickness of themask is preferably 2 to 100 μm, more preferably 5 to 60 m from theviewpoints of mechanical strength and accuracy in transfer of theorganic thin film.

[0065] In the above-described mask having the openings in a minutepattern, the openings are preferably tapered from the transfer materialside to the substrate side such that the organic thin film of thetransfer material is precisely bond to the transparent electricallyconductive layer or the other organic thin film correspondingly to theshape of the openings. The tapered shape of the opening is not limitedto that shown in FIG. 5(a).

[0066] (8) Substrate

[0067] As shown in FIG. 1(a), the substrate preferably comprises thesupport 111 and the transparent electrically conductive layer 102disposed thereon. The support and the transparent electricallyconductive layer will be described in detail later.

[0068] [2] Organic Thin Film Device

[0069] The organic thin film device according to the present inventionmay comprise such a lamination structure on the support as: transparentelectrically conductive layer/light-emitting organic thin film/back sideelectrode; transparent electrically conductive layer/light-emittingorganic thin film/electron-transporting organic thin film/back sideelectrode; transparent electrically conductive layer/hole-transportingorganic thin film/light-emitting organic thin film/electron-transportingorganic thin film/back side electrode; transparent electricallyconductive layer/hole-transporting organic thin film/light-emittingorganic thin film/back side electrode; transparent electricallyconductive layer/light-emitting organic thin film/electron-transportingorganic thin film/electron-injecting organic thin film/back sideelectrode; transparent electrically conductive layer/hole-injectingorganic thin film/hole-transporting organic thin film/light-emittingorganic thin film/electron-transporting organic thinfilm/electron-injecting organic thin film/back side electrode; thereversed structure thereof; etc. The light-emitting organic thin filmcomprises a light-emitting compound and light emission is generallyallowed from the transparent electrically conductive layer side.Examples of materials for each organic thin film are described in“Organic EL Display” (Technotimes Co., Separate Volume of “MonthlyDisplay”, the October issue of 1998), etc.

[0070] (1) Substrate

[0071] (a) Support

[0072] Examples of material used for the support include: inorganicmaterials such as yttrium-stabilized zirconia (YSZ) and glasses; polymermaterials such as polyesters (polyethylene terephthalate, polybutyleneterephthalate, polyethylene naphthalate, etc.), polystyrene,polycarbonates, polyethersulfones, polyarylates, allyldiglycolcarbonate,polyimides, polycyclolefins, norbornene resins,poly(chlorotrifluoroethylene), teflon andpolytetrafluoroethylene-polyethylene copolymer; etc. The support may bemade of one material or a plurality of materials. Among the materials,preferred are the polymer materials to produce a flexible organic thinfilm device and more preferred are such that is excellent in heatresistance, dimensional stability, solvent resistance, insulationproperty and workability and poor in gas permeability andhygroscopicity, for example, polyesters, polycarbonates,polyethersulfones, fluorine-containing polymer materials such aspoly(chlorotrifluoroethylene), teflon andpolytetrafluoroethylene-polyethylene copolymer.

[0073] Shape, structure and size of the support may be appropriatelyselected in accordance with purposes and applications of the organicthin film device. The support is generally in a plate-shape. The supportmay have a single-layer structure or a multi-layer structure. Thesupport may be composed of one member or a plurality of members. Thesupport may be colorless or colored, however, it is preferable that thesupport is colorless and transparent such that light emitted from thelight-emitting organic thin film is not scattered or damped.

[0074] On one surface or the both surfaces of the support may bedisposed a moisture permeation-inhibiting layer and/or a gas barrierlayer. Such layers are preferably made of an inorganic compound such assilicon nitride, silicon oxide, etc. The moisture permeation-inhibitinglayer and the gas barrier layer may be provided by a radio frequencysputtering method, etc. Further, a hard coating layer and anundercoating layer may be disposed on the support, if necessary.

[0075] (b) Transparent Electrically Conductive Layer (TransparentElectrode)

[0076] The transparent electrically conductive layer generally acts tosupply positive holes to the organic thin films as a positive electrode.The transparent electrically conductive layer may act as a negativeelectrode, and in this case, the back side electrode acts as thepositive electrode. The explanations will be made with respect to thecase of using the transparent electrically conductive layer as thepositive electrode.

[0077] Shape, structure and size of the transparent electricallyconductive layer are not particularly limited and may be appropriatelyselected in accordance with applications and purposes of the organicthin film device. The transparent electrically conductive layer may bemade of a metal, an alloy, a metal oxide, an electrically conductivecompound, a mixture thereof, etc. The transparent electricallyconductive layer is preferably made of a material having a work functionof 4 eV or more. Examples of the material for the transparentelectrically conductive layer include: antimony-doped tin oxide (ATO);fluorine-doped tin oxide (FTO); semiconductive metal oxides such as tinoxide, zinc oxide, indium oxide, indium tin oxide (ITO) and indium zincoxide (IZO); metals such as gold, silver, chromium and nickel; mixturesand laminations of the metal and a conductive metal oxide; inorganicconductive compounds such as copper iodide and copper sulfide; organicconductive compounds such as polyaniline, polythiophene and polypyrrole;laminations Lithe organic conductive compound and ITO; etc.

[0078] Method for forming the transparent electrically conductive layeris not particularly limited and may be appropriately selected dependingon the material used therefor from: wet methods such as printing methodsand coating methods; physical methods such as vacuum deposition methods,sputtering methods and ion-plating methods; chemical methods such as CVDmethods and plasma CVD methods; etc. For example, the transparentelectrically conductive layer of ITO is preferably disposed by a directsputtering method, an RF sputtering method, a vapor deposition method,an ion-plating method, etc. The transparent electrically conductivelayer of the organic conductive compound is preferably disposed by thewet method.

[0079] Patterning the transparent electrically conductive layer may beachieved by a chemical etching method such as a photolithography or aphysical etching method using laser, etc. In addition, the transparentelectrically conductive layer may be patterned by vacuum vapordeposition or sputtering while masking, a lift-off method, a printingmethod, etc.

[0080] Although the position of the transparent electrically conductivelayer in the organic thin film device is not particularly limited andmay be appropriately selected in accordance with applications andpurposes of the organic thin film device, the transparent electricallyconductive layer is preferably disposed on the support. The transparentelectrically conductive layer may be disposed on the whole surface or apart of the support.

[0081] Thickness of the transparent electrically conductive layer may beproperly controlled depending on the material used therefor. Thethickness is generally 10 nm to 50 m, preferably 50 nm to 20 μm. Theresistance of the transparent electrically conductive layer ispreferably 10³ Ω/square or less, more preferably 10² Ω/square or less.The transparent electrically conductive layer may be colorless orcolored. Light transmittance of the transparent electrically conductivelayer is preferably 60% or more, more preferably 70% or more to allowlight emission from the transparent electrically conductive layer side.The light transmittance can be measured by a known method using aspectrophotometer.

[0082] Further, electrodes disclosed in “Tomei-Dodenmaku no Shintenkai(Development of the Transparent Electrically Conductive Film)”supervised by Yutaka Sawada, CMC, Ink., 1999, etc. may be used as thetransparent electrically conductive layer. Particularly in the case ofusing a plastic support poor in heat resistance, it is preferable thatthe transparent electrically conductive layer is made of ITO or IZO andformed at a low temperature of 150° C. or less.

[0083] (2) Back Side Electrode

[0084] The back side electrode generally acts to supply electrons to theorganic thin films as the negative electrode. The back side electrodemay act as the positive electrode, and in this case, the abovetransparent electrically conductive layer acts as the negativeelectrode. The explanations will be made with respect to the case ofusing the back side electrode as the negative electrode.

[0085] Shape, structure and size of the back side electrode are notparticularly limited and may be appropriately selected in accordancewith applications and purposes of the organic thin film device. The backside electrode may be made of a metal, an alloy, a metal oxide, anelectrically conductive compound, a mixture thereof, etc. The back sideelectrode is preferably made of a material having a work function of 4.5eV or less. Examples of the material used for the back side electrodeinclude: alkali metals such as Li, Na, K and Cs; alkaline earth metalssuch as Mg and Ca; gold; silver; lead; aluminum; a sodium-potassiumalloy; a lithium-aluminum alloy; a magnesium-silver alloy; indium; rareearth metals such as ytterbium; etc. Although the materials may be usedsingly, it is preferable that the back side electrode is made of aplurality of materials to improve both of stability and electroninjection property. Among the materials, alkali metals and alkalineearth metals are preferred from the viewpoint of the electron injectionproperty and aluminum-based materials are preferred from the viewpointof the stability during storage. Used as the aluminum-based material aresimple substance of aluminum, and alloys and mixtures comprisingaluminum and 0.01 to 10 weight % of alkali metal or alkaline earth metalsuch as a lithium-aluminum alloy, a magnesium-aluminum alloy, etc. Theback side electrode may be made of a material disclosed in JapanesePatent Laid-Open Nos. 2-15595 and 5-121172, etc.

[0086] Method for forming the back side electrode is not particularlylimited, and may be appropriately selected depending on the materialused therefor from: wet methods such as printing methods and coatingmethods; physical methods such as vacuum deposition methods, sputteringmethods and ion-plating methods; chemical methods such as a CVD methodand a plasma CVD method; etc. In the case of using a plurality ofmaterials for the back side electrode, the materials may be spatteredsimultaneously or in order.

[0087] Patterning the back side electrode may be achieved by a chemicaletching method such as a photolithography or a physical etching methodusing laser, etc. In addition, the back side electrode may be patternedby vacuum vapor deposition or sputtering while masking, a lift-offmethod, a printing method, etc.

[0088] Although the position of the back side electrode in the organicthin film device is not limited and may be appropriately selected inaccordance with applications and purposes of the organic thin filmdevice, the back side electrode is preferably disposed on the organicthin films. The back side electrode may be disposed on the whole surfaceor a part of the organic thin films. Further, a dielectric layer may bedisposed between the back side electrode and the organic layer. Thedielectric layer may be made of a fluorinated alkali metal or analkaline earth metal and may have a thickness of 0.1 to 5 nm. Thedielectric layer may be formed by a vacuum vapor denosition method, aspattering method, an ion-plating method, etc.

[0089] Thickness of the back side electrode may be properly controlleddepending on the material used therefor. The thickness is generally 10nm to 5 μm, preferably 50 nm to 1 μm. The back side electrode may betransparent or opaque. The transparent back side electrode may be alaminate composed of a thin layer of the above-mentioned material havinga thickness of 1 to 10 nm and a transparent conductive layer of ITO,IZO, etc.

[0090] (3) Light-Emitting Organic Thin Film

[0091] The light-emitting organic thin film comprises at least onelight-emitting compound. The light-emitting compound is not particularlylimited and may be a fluorescent compound or a phosphorescent compound.The fluorescent compound and the phosphorescent compound may be used incombination. In the present invention, the phosphorescent compound ispreferably used from the viewpoints of a light-emitting brightness and alight-emitting efficiency.

[0092] Examples of the fluorescent compound used in this inventioninclude: benzoxazole derivatives; benzoimidazole derivatives;benzothiazole derivatives; styrylbenzene derivatives; polyphenylderivatives; diphenylbutadiene derivatives; tetraphenylbutadienederivatives; naphthalimido derivatives; coumarin derivatives; perylenederivatives; perynone derivatives; oxadiazole derivatives; aldazinederivatives; pyralidine derivatives; cyclopentadiene derivatives;bis(styryl)anthracene derivatives; quinacridon derivatives;pyrrolopyridine derivatives; thiadiazolopyridine derivatives;styrylamine derivatives; aromatic dimethylidine compounds; metalcomplexes such as 8-quinolinol metal complexes and derivatives thereofand rare-earth metal complexes; light-emitting polymer material such aspolythiophene, polyphenylene, polyphenylenevinylene,polyphenylenevinylene and derivatives thereof; etc. The fluorescentcompounds may be used singly or as a mixture in combination with eachother.

[0093] The phosphorescent compound preferably utilizes triplet excitonsfor light emission. The phosphorescent compound is preferably anortho-metallation complex or a porphyrin complex. The porphyrin complexis preferably a porphyrin-platinum complex. The phosphorescent compoundmay be used singly and a plurality of the phosphorescent compounds maybe used in combination with each other.

[0094] The ortho-metallation complex used in the present invention maybe such a compound that is described in: Akio Yamamoto,“Yukikinzoku-Kagaku, Kiso to Oyo (Metalorganic Chemistry, Foundation andApplication)”, Page 150 to 232, Shokabo Publishing Co., Ltd., (1982); H.Yersin, “Photochemistry and Photophysics of Coordination Compounds”,Page 71 to 77 and 135 to 146, Springer-Verlag, Inc. (1987), etc.Although ligands of the ortho-metallation complex are not particularlylimited, the ortho-metallation complex generally has a particularligand. Preferred examples of the particular ligand include2-phenylpyridine derivatives, 7,8-benzoquinoline derivatives,2-(2-thienyl)pyridine derivatives, 2-(1-naphthyl)pyridine derivativesand 2-phenylquinoline derivatives. The derivatives may have asubstituent. The ortho-metallation complex may have a ligand other thanthe particular ligand. A central metal atom of the ortho-metallationcomplex may be selected from transition metals. The central metal ispreferably rhodium, platinum, gold, iridium, ruthenium or palladium. Theorganic thin film comprising such an ortho-metallation complex isexcellent in the light-emitting brightness and the light-emittingefficiency. Complexes disclosed in Japanese Patent No. 2000-254171,Paragraphs 0152 to 0180 may be used as the ortho-metallation complex inthe present invention.

[0095] The ortho-metallation complex used in the present invention maybe synthesized by a known method disclosed in: Inorg. Chem., 30, 1685,1991; Inorg. Chem., 27, 3464, 1988; Inorg. Chem., 33, 545, 1994; Inorg.Chim. Acta, 181, 245, 1991; J. Organomet. Chem., 335, 293, 1987; J. Am.Chem. Soc., 107, 1431, 1985; etc.

[0096] A weight ratio of the light-emitting compound in thelight-emitting organic thin film is not particularly limited. The weightratio is preferably 0.1 to 70 weight %, more preferably 1 to 20 weight %based on the total weight of the light-emitting organic thin film. Ifthe weight ratio is less than 0.1 weight % or more than 70 weight %,there is a case where the light-emitting compound cannot achievesufficient effect.

[0097] The light-emitting organic thin film may comprise a hostcompound, a hole-transporting material, an electron-transportingmaterial, an electrically inactive polymer binder, etc. if necessary.

[0098] The host compound acts to accelerate light emission of thelight-emitting compound such that the host compound is excited andenergy is transferred from the excited host compound to thelight-emitting compound. Examples of the host compound include:carbazole derivatives; triazole derivatives; oxazole derivatives;oxadiazole derivatives; imidazole derivatives; polyarylalkanederivatives; pyrazoline derivatives; pyrazolone derivatives;phenylenediamine derivatives; arylamine derivatives; amino-substitutedchalcone derivatives; styrylanthracene derivatives; fluorenonederivatives; hydrazone derivatives; stilbene derivatives; silazanederivatives; aromatic tertiary amine compounds; styrylamine compounds;aromatic dimethylidyne compounds; porphyrin compounds;anthraquinodimethane derivatives; anthrone derivatives; diphenylquinonederivatives; thiopyran dioxide derivatives; carbodimide derivatives;fluorenylidenemethane derivatives; distyrylpyrazine derivatives;anhydrides derived from a heterocyclic tetracarboxylic acid having astructure such as naphthaleneperylene; phthalocyanine derivatives;8-quinolinol metal complexes and derivatives thereof;metallophthalocyanines; metal complexes containing a benzoxazole ligandor a benzothiazole ligand; polysilane compounds; poly(N-vinylcarbazole)derivatives; aniline copolymers; electrically conductive polymers andoligomers such as oligothiophenes and polythiophenes; polythiophenederivatives; polyphenylene derivatives; polyphenylenevinylenederivatives; polyfluorene derivatives; etc. The host compound may beused singly or in combination with other host compound.

[0099] The hole-transporting material are not particularly limited andmay be a low molecular weight material or a high molecular weightmaterial if it has any function of: injecting the holes provided fromthe positive electrode into the light-emitting organic thin film;transporting the holes; and blocking the electrons provided from thenegative electrode. Examples of the hole-transporting material includecarbazole derivatives, triazole derivatives, oxazole derivatives,oxadiazole derivatives, imidazole derivatives, polyarylalkanederivatives, pyrazoline derivatives, pyrazolone derivatives,phenylenediamine derivatives, arylamine derivatives, amino-substitutedchalcone derivatives, styrylanthracene derivatives, fluorenonederivatives, hydrazone derivatives, stilbene derivatives, silazanederivatives, aromatic tertiary amine compounds, styrylamine compounds,aromatic dimethylidyne compounds, porphyrin compounds, polysilanecompounds, poly(N-vinylcarbazole) derivatives, aniline copolymers,electrically conductive polymers and oligomers such as oligothiophenesand polythiophenes, polythiophene derivatives; polyphenylenederivatives; polyphenylenevinylene derivatives; polyfluorenederivatives; etc. The hole-transporting material may be used singly orin combination with other hole-transporting material.

[0100] The electron-transporting material are not particularly limitedif only it has any function of: injecting the electrons provided fromthe negative electrode into the light-emitting organic thin film;transporting the electrons; and blocking the holes provided from thepositive electrode. Examples of the electron-transporting materialinclude: triazole derivatives; oxazole derivatives; oxadiazolederivatives; fluorenone derivatives; anthraquinodimethane derivatives;anthrone derivatives; diphenylquinone derivatives; thiopyran dioxidederivatives; carbodimide derivatives; fuorenylidenemethane derivatives;distyrylpyrazine derivatives; anhydrides derived from a heterocyclictetracarboxylic acid having a structure such as naphthaleneperylene;phthalocyanine derivatives; 8-quinolinol metal complexes and derivativesthereof; metallophthalocyanines; metal complexes containing abenzoxazole ligand or a benzothiazole ligand; aniline copolymers;electrically conductive polymers and oligomers such as oligothiophenesand polythiophenes; polythiophene derivatives; polyphenylenederivatives; polyphenylenevinylene derivatives; polyfluorenederivatives; etc.

[0101] Examples of the electrically inactive polymer binder include:polyvinyl chloride; polycarbonates; polystyrene; poly(methylmethacrylate); poly(butyl methacrylate); polyesters; polysulfones;polyphenylene oxide; polybutadiene; hydrocarbon resins; ketone resins;phenoxy resins; polyamides; ethylcellulose; poly(vinyl acetate); ABSresins; polyurethanes; melamine resins; unsaturated polyesters; alkydresins; epoxy resins; silicone resins; polyvinylbutyral;polyvinylacetal; etc. The light-emitting organic thin film containingthe polymer binder can be easily formed by the wet film-forming methodwith a large area.

[0102] Thickness of the light-emitting organic thin film is preferably10 to 200 nm, more preferably 20 to 80 nm. The light-emitting organicthin film having the thickness of more than 200 nm often requiresincreased driving voltage. On the other hand, when the thickness is lessthan 10 nm, there is a case where the organic thin film deviceshort-circuits.

[0103] (4) Hole-Transporting Organic Thin Film

[0104] The organic thin film device may comprise the hole-transportingorganic thin film if necessary. The hole-transporting organic thin filmmay be composed of the above-mentioned hole-transporting material. Thehole-transporting layer may further contain the polymer binder mentionedabove. Thickness of the hole-transporting organic thin film ispreferably 10 to 200 nm, more preferably 20 to 80 nm. The thickness ofmore than 200 nm often increases the driving voltage for the organicthin film device, and the thickness of less than 10 nm often results inshort-circuit of the organic thin film device.

[0105] (5) Electron-Transporting Organic Thin Film

[0106] The organic thin film device may comprise theelectron-transporting organic thin film if necessary. Theelectron-transporting organic thin film may be composed of theabove-mentioned electron-transporting material. Theelectron-transporting organic thin film may further contain the polymerbinder mentioned above. Thickness of the electron-transporting organicthin film is preferably 10 to 200 nm, more preferably 20 to 80 nm. Thethickness of more than 200 nm often increases the driving voltage forthe organic thin film device, and the thickness of less than 10 nm oftenresults in short-circuit of the organic thin film device.

[0107] (6) Others

[0108] The organic thin film device of the present invention maycomprise the protective layer disclosed in Japanese Patent Laid-OpenNos. 7-85974, 7-192866, 8-22891, 10-275682 and 10-106746, etc. Theprotective layer is generally disposed on the uppermost surface of theorganic thin film device. In the organic thin film device where thesupport, the transparent electrically conductive layer, the organic thinfilms and the back side electrode are disposed in this order, theuppermost surface is the outer surface of the back side electrode.Further, in the organic thin film device where the support, the backside electrode, the organic thin films and the transparent electricallyconductive layer are disposed in this order, the uppermost surface isthe outer surface of the transparent electrically conductive layer.Shape, size and thickness of the protective layer are not particularlylimited. The protective layer may be made of any material that canprevent a substance such as water and oxygen, which can degrade thefunction of the organic thin film device, from entering or penetratinginto the device. Silicon oxide, silicon dioxide, germanium oxide,germanium dioxide, etc. may be used for the protective layer.

[0109] A method for forming the protective layer is not particularlylimited and the protective layer may be formed by a vacuum depositionmethod, a sputtering method, an activated sputtering method, a molecularbeam epitaxy method (MBE method), a cluster ion beam method, anion-plating method, a plasma polymerization method, a plasma CVD method,a laser CVD method, a thermal CVD method, a coating method, etc.

[0110] It is preferred that a sealing layer is disposed in the organicthin film device to prevent invasion or permeation of water or oxygeninto the device. Examples of a material for the sealing layer include:copolymers of tetrafluoroethylene and at least one comonomer;fluorine-containing copolymers having a cyclic structure in the mainchain; polyethylene; polypropylene; poly(methyl methacrylate);polyimides; polyureas; polytetrafluoroethylene;polychlorotrifluoroethylene; polydichlorodifluoroethylene; copolymers ofchlorotrifluoroethylene or dichlorodifluoroethylene and anothercopolymer; a moisture-absorbing substance having a water absorption of1% or more; a moisture-resistant substance having a water absorption of0.1% or less; metals such as In, Sn, Pb, Au, Cu, Ag, Al, Ti and Ni;metal oxides such as MgO, SiO, SiO₂, Al₂O₃, GeO, NiO, CaO, BaO, Fe₂O₃,Y₂O₃, and TiO₂; metal fluorides such as MgF₂, LiF, AIF₃ and CaF₂; liquidfluorinated carbons such as perfluoroalkanes, perfluoroamines andperfluoroethers; dispersions prepared by adding an adsorbent foradsorbing moisture or oxygen to the liquid fluorinated carbon; etc.

[0111] In the organic thin film device of the present invention, the oneor more organic thin films may be sealed by sealing parts such as asealing plate and a sealing vessel to shield the device from invasion orpenetration of moisture, oxygen, etc. The sealing parts may be disposedonly on the back side electrode side. Alternatively, the entirelight-emitting structure may be covered with the sealing parts. Shape,size and thickness of the sealing parts are not particularly limited ifonly the sealing parts can seal and shield the organic thin films fromthe external air. The sealing parts may be made of: a glass; a stainlesssteel; a metal such as aluminum; a plastic such aspoly(chlorotrifluoroethylene), polyester and polycarbonate; a ceramic;etc.

[0112] A sealing agent or an adhesive may be used when the sealing partsare disposed on the light-emitting structure. In the case of coveringthe entire light-emitting structure with the sealing parts, portions ofthe sealing parts may be heat-welded with each other without the sealingagent. Used as the sealing agent may be an ultraviolet-hardening resin,a thermosetting resin, a two-part type hardening resin, etc. Among them,the ultraviolet-hardening resin is preferable.

[0113] Further, a water-absorbing agent or an inert liquid may beinterposed between the light-emitting structure and the sealing parts.The water-absorbing agent is not particularly limited and may be bariumoxide, sodium oxide, potassium oxide, calcium oxide, sodium sulfate,calcium sulfate, magnesium sulfate, phosphorus pentoxide, calciumchloride, magnesium chloride, copper chloride, cesium fluoride, niobiumfluoride, calcium bromide, vanadium bromide, a molecular sieve, azeolite, magnesium oxide, etc. The inert liquid is also not particularlylimited and may be: paraffin; liquid paraffin; a fluorine-containingsolvent such as perfluoroalkane, perfluoroamine and perfluorether; achlorine-containing solvent; silicone oil; etc.

EXAMPLES

[0114] The present invention will be explained in further detail by thefollowing examples without intention of restricting the scope of thepresent invention defined by the claims attached hereto.

Example 1

[0115] Polyvinylcarbazole with Mw of 63,000 manufactured by AldrichChemical Co. and an ortho-metallation complex of tris(2-phenylpyridine)iridium complex were dissolved in dichloroethane to prepare anapplication liquid. Weight ratio ofpolyvinylcarbazole:tris(2-phenylpyridine) iridium complex was 40:1 inthe application liquid. The application liquid was applied to atemporary substrate of PET film having a thickness of 5 μm manufacturedby TEIJIN LIMITED by means of a bar-coater and dried at roomtemperature, to prepare a first transfer material comprising thetemporary substrate and a light-emitting organic thin film having athickness of 40 nm.

[0116] Polyvinylbutylal with Mw of 50,000 manufactured by AldrichChemical Co. and a compound of the following formula were dissolved in1-butanol to prepare an application liquid. Weight ratio ofpolyvinylbutylal: the compound of the following formula was 10:20 in theapplication liquid. The application liquid was applied to a temporarysubstrate of PET film having a thickness of 5 μm manufactured by TEIJINLIMITED by means of an extrusion coating apparatus and dried under avacuum condition at 80° C. for 2 hours, to prepare a second transfermaterial comprising the temporary substrate and an electron-transportingorganic thin film having a thickness of 60 nm.

[0117] A support of a glass plate having a thickness of 0.5 mm and asize of 2.5 cm×2.5 cm was put into a vacuum chamber and thereon wasformed an ITO transparent electrode by DC magnetron sputtering using anITO target under a condition where a temperature of the support was 250°C. and an oxygen pressure was 1×10⁻³ Pa. The ITO target had SnO₂-contentof 10 weight % and a mole ratio of indium/tin was 95/5. The ITOtransparent electrode had a thickness of 0.2 μm and a surface resistanceof 10 Ω/square.

[0118] The support with the ITO transparent electrode was put into awashing vessel and washed with isopropyl alcohol (IPA), and thensubjected to an oxygen plasma treatment. The ITO transparent electrodewas spin-coated with poly(ethylenedioxythiophene)-polystyrene sulfonicacid aqueous dispersion (“Baytron P” manufactured by BAYER AG., solidcontents: 1.3%) and vacuum-dried at 150° C. for 2 hours to form ahole-transporting organic thin film having a thickness of 100 nm.

[0119] As shown in FIG. 2, the first transfer material was made to facethe hole-transporting organic thin film, and brought in tight contactthereto under a vacuum condition. The resultant was heated from thefirst transfer material side by an infrared lamp at 110° C., and then,the temporary substrate was peeled off to transfer the light-emittingorganic thin film onto the hole-transporting organic thin film.

[0120] The second transfer material was brought in tight contact tothus-formed light-emitting organic thin film under a vacuum condition asshown in FIG. 2. The resultant was heated from the second transfermaterial side by the infrared lamp at 110° C., and then, the temporarysubstrate was peeled off to transfer the electron-transporting organicthin film onto the light-emitting organic thin film.

[0121] Then, on the electron-transporting organic thin film was placed amask patterned such that a light-emitting device has a light-emittingarea of 5 mm×5 mm. The resultant was put into a vapor depositionapparatus, and a back side electrode was formed on theelectron-transporting organic thin film by vapor depositing magnesiumand silver with a mole ratio of magnesium/silver=10/1 into a thicknessof 0.25 μm and by vapor depositing silver into a thickness of 0.3 μm.Aluminum lead wires were connected to the transparent electrode and theback side electrode to provide a light-emitting structure.

[0122] The resulting light-emitting structure was put into a glove boxreplaced with a nitrogen gas, and sealed with a sealing vessel of aglass by an ultraviolet-hardening adhesive “XNR5493” manufactured byNagase-Chiba Co. to produce an organic EL device of Example 1.

[0123] Thus-obtained organic EL device of Example 1 was made to emitlight while applying direct voltage thereto by “Source-Measure Unit2400” manufactured by TOYO CORPORATION. As a result, the organic ELdevice exhibited a light-emitting efficiency of 1% when it emits lightwith a brightness of 200 cd/m², and the device exhibited alight-emitting efficiency of 3% when it emits light with a brightness of2000 cd/m².

Example 2

[0124] Polyvinylcarbazole with Mw of 63,000 manufactured by AldrichChemical Co. and an ortho-metallation complex of tris(2-phenylpyridine)iridium complex were dissolved in dichloroethane to prepare anapplication liquid. Weight ratio ofpolyvinylcarbazole:tris(2-phenylpyridine) iridium complex was 40:1 inthe application liquid. The application liquid was applied to thetemporary substrate of PET film having a thickness of 5 μm manufacturedby TEIJIN LIMITED by means of a micro-gravure coater and dried, to forma blue light-emitting organic thin film (blue pixels) having a thicknessof 40 nm into a pattern with a width of 300 μm and a length of 600 μm.

[0125] Polyvinylcarbazole with Mw of 63,000 manufactured by AldrichChemical Co. and an ortho-metallation complex of tris(2-phenylpyridine)iridium complex were dissolved in dichloroethane to prepare anapplication liquid. Weight ratio of polyvinylcarbazole:tris(2-phenylpyridine) iridium complex was 40:1 in the applicationliquid. The application liquid was applied to the temporary substrate bymeans of the micro-gravure coater and dried, to form a greenlight-emitting organic thin film (green pixels) having a thickness of 40nm into a pattern with a width of 300 μm and a length of 600 μm.Incidentally, the application liquid was applied to the half of theregions, on which the blue light-emitting organic thin film was notdisposed.

[0126] Polyvinylcarbazole with Mw of 63,000 manufactured by AldrichChemical Co. and an ortho-metallation complex of tris(2-phenylpyridine)iridium complex were dissolved in dichloroethane to prepare anapplication liquid. Weight ratio ofpolyvinylcarbazole:tris(2-phenylpyridine) iridium complex was 40:1 inthe application liquid. The application liquid was applied to thetemporary substrate by means of the micro-gravure coater and dried, toform a red light-emitting organic thin film (red pixels) having athickness of 40 nm into a pattern with a width of 300 μm and a length of600 μm. Incidentally, the application liquid was applied to the regions,on which the blue and green light-emitting organic thin films were notdisposed.

[0127] Thus, a third transfer material comprising the temporarysubstrate and the pixels of blue, green and red provided on thetemporary substrate in the pattern was prepared. An organic EL device ofExample 2 was produced in the same manner as Example 1 except for usingthe third transfer material instead of the first transfer material.

[0128] The organic EL device of Example 2 was evaluated with respect tolight-emitting efficiency in the same manner as Example 1. As a result,the organic EL device exhibited a light-emitting efficiency of 1.2% whenit emits light with a brightness of 200 cd/m², and the device exhibiteda light-emitting efficiency of 3.1% when it emits light with abrightness of 2000 cd/m².

[0129] As described in detail above, the organic thin film device suchas the organic EL device excellent in light-emitting efficiency,uniformity of light emission and durability can be produced withexcellent efficiency and reduced cost by the method according to thepresent invention where the organic thin film is provided on thetemporary substrate by the wet method, etc. and transferred to thesubstrate. The transfer material comprising the patterned pixels ofblue, green and red on the temporary substrate may be used in thepresent invention to easily produce the fulil-color organic EL devicewith excellent accuracy. The method according to the present inventionis also advantageous in that the organic thin film can be remarkablythinned.

1-28.(cancelled)
 29. A transfer material comprising a temporarysubstrate and a at least one light-emitting organic thin film providedon the temporary substrate, the at least one light-emitting organic thinfilm comprising patterned pixels of blue, green and red.
 30. Thetransfer material of claim 29, further comprising a transparentelectrically conductive layer disposed on the temporary substrate. 31.The transfer material of claim 29, wherein the at least onelight-emitting organic thin film emits light when voltage is applied.32. The transfer material of claim 29, wherein the at least onelight-emitting organic thin film is an electroluminescent material whendirect voltage is applied.
 33. The transfer material of claim 29,wherein the thickness of the at least one light-emitting organic thinfilm is from 10 to 200 nm.
 34. The transfer material of claim 29,further comprising at least one other organic thin film, and whereintotal thickness of the at least one light-emitting organic thin film andthe at least one other organic thin film is 200 nm or less.
 35. Thetransfer material of claim 29, further comprising a hole-transportingorganic thin film and an electron-transporting organic thin film, andwherein the hole-transporting organic thin film, the at least onelight-emitting organic thin film and the electron-transporting organicthin film are disposed in this order from the substrate side.
 36. Thetransfer material of claim 29, wherein the at least one light-emittingorganic thin film is at least one solution-coated light-emitting organicthin film, and wherein the solution comprises at least one organicsolvent and at least one light-emitting organic material.
 37. Thetransfer material of 29, wherein the at least one light-emitting organicthin film is provided by applying coating solutions each containing alight-emitting compound for a color through a mask into a predeterminedpattern in order.
 38. The transfer material of claim 29, wherein thetemporary substrate has thickness of 3 to 20 μm.
 39. The transfermaterial of claim 29, wherein the at least one light-emitting organicthin film comprises at least one light-emitting compound.
 40. Thetransfer material of claim 39, wherein the at least one light-emittingcompound is at least one compound selected from the group consisting ofa fluorescent compound and a phosphorescent compound.
 41. The transfermaterial of claim 40, wherein the at least one light-emitting compoundis the phosphorescent compound.
 42. The transfer material of claim 42,wherein the phosphorescent compound is an ortho-metallation complex or aporphyrin complex.
 43. The transfer material of claim 29, wherein thelight-emitting organic thin film has a stripe pattern or atwo-dimensional grid pattern.
 44. The transfer material of claim 30,wherein the thickness of the transparent electrically conductive layeris 10 nm to 50 μm.
 45. The transfer material of claim 30, wherein thelight transmittance of the transparent electrically conductive layer is60% or more.
 46. The transfer material of claim 30, wherein theresistance of the transparent electrically conductive layer is 10³Ω/square or less.
 47. The transfer material of claim 29, wherein thetransparent electrically conductive layer comprises a material selectedfrom the group consisting of antimony-doped tin oxide, fluorine-dopedtin oxide, semiconductive metal oxides, metals, mixtures and laminationsof metal and a conductive metal oxide, inorganic conductive compoundsand organic conductive compounds.